The present invention relates in general to recording messages for a called party in a telephony system, and, more specifically, to restricting usage of recorded message files transferred within computer networks, such as an Internet Protocol (IP) network for providing IP telephony.
IP telephony is increasingly being used as the basis for telephonic communication. In addition to IP telephony calls made between networked personal computers, calls originating in the plain old telephone system (POTS) can be transported over IP networks using gateways between the public switched telephone network (PSTN) and the IP network (e.g., the Internet). IP telephony services can provide the same enhanced services that are available in a typical POTS system, such as voice mail.
When a call is made, resources in the IP network determine the address of a network location associated with the called party and establish a network session for exchanging data signals between the calling and called parties. The Session Initiation Protocol (SIP) can be used for collecting information necessary to create such a network session. A registration/location server typically provides a database of user information that may be consulted during a call set-up. The user information can be dynamically configured so that calls for a particular called party can be directed in a variety of ways. For example, a party can indicate to the location server that he/she is temporarily unavailable for receiving a call and that any incoming calls should be directed to a voice mail service for allowing a calling party to record an audio or video message for the called party. In addition, calls can be directed to the voice mail service when an incoming call initially connected to the called party's current location goes unanswered.
When an audio or video message has been recorded during a SIP-initiated communication session, the resulting multimedia file has been stored in a format ready for playback to the called party. For example, audio .wav files or video .mpg files have been created for a subsequent transfer or download to the called party via the IP network during message retrieval. File streaming can also be used to speed up the replaying of the message (e.g., transmitting packets of a streaming .wma, .wmv, or .asf file from a streaming server).
Existing SIP messaging systems require the called party to authenticate with a password or other security measure to ensure that the only the intended recipient(s) receive messages within a particular voice mailbox of a called party. However, the message files themselves are not protected. Once access to the mailbox is obtained, the message files can be copied, altered, or distributed to others without limitation. Since the message file already resides in an IP computer network, the alteration or forwarding of a message file is easily done. These uses of the recorded message may be contrary to the intention or desires of the calling party that created the message. For example, the sender of a message cannot ensure that the called party will not forward a confidential message to others.